Core recovering means



. 8, 1936. J. H. HOWARD coma RECOVERINGY MEANS 2 Sheeis-Sheet 1 Filed Aug. 5, 1935 JOHN H. Hon/Am:

Arronmsv Dec. 8, 1936. J HOWARD 2,063,437

GORE RECOVERING MEANS Filed Aug. 5, 1955 2 Sheets-Sheet 2 JOIfN h. HOWARD INVENMR A TT'OPNEY Patented Dec. 8, 1936 UNITED STATES PATENT OFFICE CORE RECOVERING MEANS John H. Howard, Huntington Park, Calif.

Application August 5,

15 Claims.

This. invention has to do with well drilling tools and has particular reference to well core drills. A general object of this invention is to provide a practical, effective and improved core catcher or core recovering means for use or embodiment in a core drill.

Core catchers are provided in well core drills to grip and retain the cores of the earth formation when the drills are raised and withdrawn from the wells so that the cores are recovered for examination. One class of core catcher that is in general use embodies a ring like body shiftable in the drill, springs depending from the ring and slips carried by the springs and operable inwardly to grip the core throughcooperation with an inclined surface on the interior of the tool. It has been found that the slips suspended from the body work downwardly on the inclined surface as the tool is run into the well and thus are often in the fully actuated position before the actual coring operation is begun. When this condition exists the core entering the drill encounters the actuated slips and is either broken up or partially destroyed by this engagement or causes the springs carrying the slips to be bent back upon themselves so that they are broken or distorted to the extent that the slips are made inoperative.

Another object of this invention is to provide a core catcher that does not interfere with the free entrance of the core into the drill and that is operable to dependably recover and retain the core with a minimum of mutilation of the core.

Another object of this invention is to provide a core catcher embodying slips that are mounted and positioned so that they are readily retracted by the entering core and so that the engagement of the entering core with the slips does not endanger the springs carrying the slips.

Another object of this invention is to provide a core catcher embodying slips located above the core catcher body and connected therewith by springs, this locating of the slips being such that the slips are less liable to mutilate the entering core and such that the springs are not subjected to distorting or fracturing strains.

Another object of this invention is to provide a core catcher of the character mentioned in which the body carries spring pressed core gripping dogs which are engaged by the entering core to resist movement of the body so that the slips are automatically freed or released in the event that they have become prematurely actuated.

Another object of this invention is to provide 1935, Serial No. 34,649

a core catcher of the character mentioned that is free to float or be non-rotatable during the rotation of the drill so that the engagement of its core engaging parts with the core does not mutilate the core or cause excessive wear of the 5 parts.

Another object of this invention is to provide a core catcher of the character mentioned that includes a ring or sleeve arranged to float or rotate in the drill and having an inclined inner surface for cooperating with or actuating the slips, the relationship between the sleeve and slips being such that the core catcher is entirely free to float in the drill. Core catchers have been introduced having rotatable or floating bodies and slips connected with the body which bear directly on inclined surfaces of the rotating drill. This direct engagement of the slips with the drill causes or tends to cause the core catcher to rotate with the drill so that its core engaging parts mutilate the core. As distinguished from. such prior devices the core catcher of the present invention has slips acting on or engaging a floating sleeve whereby the entire core catcher is free to float or remain stationary with the core.

Another object of this invention is to provide a core catcher that is easily and quickly disengaged from the recovered core when the drill is disassembled at the derrick. When the drill is taken apart at the derrick the core catcher is entirely free of the other parts of the drill and may be easily removed from the core instead of forcing the core through the core catcher as has been the common practice heretofore.

A further object of this invention is to provide a core catcher of the character mentioned that is simple and inexpensive of manufacture and dependable in operation.

The various objects and features of my invention will be fully understood from the following detailed description of a typical preferred form and application of the invention, throughout which description reference is made to the accompanying drawings, in which:

Fig. 1 is a side elevation of a core drill embodying the core recovering means or core catcher of this invention with the lower portion of the drill and the core catcher in vertical cross section. Fig. 2 is an enlarged vertical detailed secso tional view of a portion of the drill and the core catcher. Fig. 3 is a transverse detailed sectional view taken substantially as indicated by line 3-3 on Fig. 2. Fig. 4 is an enlarged vertical detailed sectional view of the core catcher removed from the drill being a view taken substantially as indicated by line 4-4 on Fig. 3. Fig. 5 is a transverse detailed'sectional view taken as indicated by line 55 on Fig. 4 and Fig. 6 is an enlarged side elevation of the sleeve embodied in the core catcher with a portion broken away to appear in vertical cross section.

The core catcher of the present invention is adapted to be employed in core drills varying somewhat in character. In the following detailed description the core catcher will be described in connection with a core drill construction of the general character set forth and fully claimed in the copending application of John H. Howard and Alfred C. Catland, Serial No. 27,704, filed June 21, 1935, entitled Core recovering tool which is well suited for the reception of or inclusion of the core catcher, it being understood that the invention is not to be taken as restricted to this particular use or application.

The core drill illustrated in the drawings includes an outer barrel I adapted to be connected with the lower end of a well drilling string and having a sub I I on its lower end. The sub I I is provided at its lower end with a tapered pin I2 and a bit head sub I3 is threaded on the pin. A reduced tapered pin I4 is provided on the lower end of the sub I3. A tubular bit head I5 is screw-threaded on the pin I4. The bit head I5 includes or carries a suitable cutting means for making an annular cut in the earth formation. In the particular drill illustrated in the drawings the bit head I5 carries a plurality of roller cutters I6 rotatably supported on pins I1 and projecting from the lower end of the bit head to act on the formation at the bottom of the well bore. The core formed or left by the cutters I6 is adapted to enter the opening I8 of the bit head and pass upwardly through the opening I9 of the sub I3.

An inner barrel is arranged longitudinally within the outer barrel III to receive the core. The inner barrel 20 is spaced from the interior of the outer barrel III and the sub II leaving an annular fluid passage 2I. The upper portion of the sub opening I9 is of enlarged diameter and a longitudinally extending tube or sleeve 12 is arranged in the opening and welded to the sub I3 at a shoulder 23. The sleeve 22 is spaced from the wall of the enlarged portion of the opening I 9 leaving an annular fluid passage 24. The upper end of the sleeve 22 is flat and horizontal and is spaced below the lower end of the pin I2 leaving the passage 24 open at its upper end. A groove 25 is provided in the upper end of the bit head I4 to register with a plurality of circumferentially spaced ports 26 which conduct the circulation fluid downwardly from the annular passage 24. Spaced ports 21 are provided in the bit head I5 and extend downwardly from the groove 25 to discharge the circulation fluid against the cutters I6.

An annular upwardly facing shoulder 28 is provided on the interior of the sleeve 22 to support a part of the core catcher as will be hereinafter described. The inner barrel 20 is provided with an enlargement or bearing part 29. The bearing part 29 is adapted to rotatably support the inner barrel at its lower end and has a downwardly facing shoulder 30 for cooperating with the upper end of the sleeve 22. The bearing part 29 extends downwardly into the sleeve 22 and its lower end forms a downwardly facing shoulder 3| in the sleeve. An upwardly facing shoulder 32 on the bearing part 29 carries a hardened bushing 33 adapted to bear upwardly against the lower end of the pin I2 when the engagement of the core with the inner barrel I2 holds the inner barrel upwardly while the drill is being fed downwardly. Spaced ports 34 are provided in the bearing part 29 to conduct the circulation fluid from the annular passage 2I to the annular passage 24.

The core catcher of the present invention includes, generally, a, ring or body 35 adapted to shift and float in the opening 36 of the sleeve 22, pivoted core engaging dogs 31 on the body 35, a floating sleeve 38 in the opening 36 and slips 39 connected with the body 35 and actuated through the cooperation with the sleeve 38.

The body 35 is an annular or tubular structure aranged for movement and rotation in the opening 36 of the sleeve 22. The opening 36 of the sleeve forms a continuation of the opening I9 in the sub I3 and the upper portion of the opening I9 may be of enlarged diameter to have its well flush with the wall of the opening 36. The core catcher body 35 is preferably sectional comprising an inner ring section 40 and an outer ring section H. The ring section 4I surrounds the upper portion of the section 40 and the upper ends of the two sections may be flush. The ring 4| is shorter than the ring 40 having its lower end spaced some distance above the lower end of the body 35. The two ring sections 40 and 4| are detachably or removably connected by circumferentially spaced pairs of vertically spaced rivets 42. An annular groove 43 is provided in the periphery of the inner ring section 40 and its outer side is closed by the surrounding outer section 4|. The body 35 is proportioned so that it may move in the opening 36 with suitable freedom or clearance. The downward movement of the core catcher body 35 may be limited by spaced upwardly facing shoulders 44 on the wall of the opening I9. The upward movement of the core catcher body 35 is limited by the sleeve 38 as will be hereinafter described.

The dogs 31 are arranged on the body 35 to project from its interior for engaging the core to resist movement of the body 35 and to bite into the core and assist the slips 39 in retaining the core when the drill is withdrawn from the well. In practice there is a plurality of circumferentially spaced dogs pivoted at spaced openings or recesses 45 in the body 35. Pins 46 extend through transverse openings 41 in the dogs 31 and have their opposite end portions carried in the groove 43 to pivotally support the dogs on the body 35. Flat faces 48 on the pins 46 cooperate with the wall of the groove 43 to prevent turning and longitudinal shifting of the pins 46. The recesses 45 are Open at the periphery of the body 35 and the dogs 31 have cam parts 49 projecting outwardly from the open outer ends of the recesses for cooperating with one of the shoulders 44 to urge the dogs 31 downwardly when the core catcher is actuated. The inwardly projecting active portions of the dogs 31 have upper and lower surfaces which converge to relatively sharp edges for cutting or biting into the core. Each dog 31 has a bearing surface 50 adapted to rest on or cooperate with the lower wall of a recess 45 when the dog reaches its fully actuated position. The recesses 45 preferably continue upwardly on the interior of the body 35 to the upper end of the body so that they may receive the dogs 31 when the dogs are pivoted to their up positions by contact with the core.

In the preferred form of the invention the dogs a are of different lengths to be effective in gripping and supporting cores of different diameters and soft cores, as well as hard cores. In the case illustrated in the drawings there are three relatively long dogs 31 and three relatively short dogs spaced between the long dogs. Spring means are provided for yieldingly urging the dogs 31 into active engagement with the core. Notches or.s1ots are provided in the outer pivoted portions of the dogs to intersect the openings 41. Torsional springs 52 surround the pins 48 within the slots 5|. The ends of the springs 52 react against the dogs and the body 35 so that the springs tend to pivot the active ends of the dogs downwardly and inwardly against the core.

The sleeve 38 is arranged within the opening 38 of the sleeve 22 between the shoulders 28 and 3|. The sleeve 38 is provided to cooperate with and actuate the dogs 39. In accordance with the invention the sleeve 38 is a simple, annular or tubular member having a plain cylindric periphery. The sleeve 38 is prevented from moving longitudinally to any appreciable extent by the opposing shoulders 28 and 3| but is free to float or to rotate relative to the drill. The interior or inner surface 54 of the sleeve 38 is inclined downwardly and inwardly to cooperate with the slips 39. The lower inner corner of the sleeve 38 may be rounded as illustrated in Figs. 1, 2, 4 and 6 of the drawings. Longitudinally extending grooves 55 are provided in the interior of the sleeve 38. The grooves 55 are circumferentially spaced and may have flat vertical inner or bottom walls.

The slips 39 are adapted to be actuated through cooperation with the sleeve 38 to grip the core and assist the dogs 31 in freeing the core from the formation and in supporting the core when the drill is withdrawn from the well. It is a feature of the invention that the core gripping slips 39 are located above the body 35. The slips 39 are located within the sleeve 38 to engage or cooperate with its inclined inner surface 54. There is a plurality of circumferentially spaced slips 39 arranged around the interior of the sleeve 38, a slip being positioned at each groove 55. The slips 39 have downwardly and inwardly inclined outer surfaces 58 for slidably engaging or hearing on the inner surface 54 of the sleeve 38. The inner sides of the slips 39 are provided with upwardly and inwardly facing teeth 51 for biting into the core.

In accordance with the invention the slips 39 are connected with the body 35 to move therewith. Spring members or flexible members 58 connect the slips 39 with the core catcher body 35. The flexible members 58 may be riveted or otherwise connected with the body 35 and project upwardly from the upper end of the body to extend through the grooves 55. In the preferred construction illustrated in the drawings the flex ible members 58 extend into grooves or openings 58 between the two body sections 48 and 4| and are secured to the body by the rivets 42. Thus the rivets 42 operate to hold the body sections 48 and 4| assembled, hold the pins 48 in place and attach the flexible members 58 to the body. The flexible members 58 are preferably vertical to extend through the grooves 55 with suitable freedom. The upper end portions of the flexible members 58 are received in recesses 6| in the outer sides of the slips 59. Rivets 52 may secure the slips 39 to the flexible members 58. The heads of the rivets 52 are preferably countersunk in the active inner sides of the slips. The spring members 58 preferably urge-or hold the slips 39 outwardly against the surface 54 of the sleeve 38.

It will be noted that the engagement of the flexible members 58 in the grooves 55 connects the sleeve 38 with the core catcher body 35 for rotation with the body. The sleeve 38 is proportioned so that its lower end is engageable by the upper end of the body 85 to limit the upward movement of the body. The resiliency of the flexible members 58 urges the slips 39 outwardly against the inclined surface 54 to normally or initially retain the slips at the upper portion of the inclined surface. When the slips 39 are in. this position the body 35 is adjacent the lower end of the sleeve 38 as illustrated in Figs. 1 and 2 of the drawings.

In operation the drill and the core catcher are assembled as illustrated throughout the drawings and the drill is run into the well on the lower end of a drilling string. The drilling string is rotated and fed downwardly in the usual manner so that the cutters it make an annular cut and leave a core. As pointed out above, the resiliency of the flexible members 58 tends to hold the slips outwardly against the surface 54 so that the slips remain on the upper portion of the surface. Accordingly the flexible members tend to hold the slips in their retracted or inactive positions. As the core is formed and received in the openings I8 and I9 its upper end is engaged by the spring pressed dogs 31. The engagement of the core with the dogs 31 holds or tends to hold the core catcher body 35 and the parts connected therewith against rotation and longitudinal movement. Thus, in the event that the slips 39 have worked downwardly on the surface 54 the core engaging the spring urged dogs 31 may hold the body 35 against movement while the drill is fed downwardly so that the inclined surface 54 moves downwardly relative to the slips 39, permitting the slips to move to their out or retracted positions. It is to be understood that the pivoted dogs 31 retract or pivot upwardly and outwardly as they engage the core during the downward feeding and rotating of the drill. Thus the core is freely received or passed through the core catcher body without mutilation.

Under most conditions the slips 39 will be in their out or retracted positions when they approach the upper end of the core. In some cases,

however, the slips 39 may be tightly wedged in their actuated or partially actuated positions so that they engage the upper end of the core as the drilling proceeds. This engagement of the slips 39 with the upper end of the care does not result in material mutilation of the core and does not cause bending or fracturing of the flexible members 58 as the strain applied to the flexible members is a simple tensile strain. In other words, the slips 39 moving downwardly with the drill due to their connection with the body 35 by the spring members 58, engage the upper end of the stationary core to put the spring members 58 under tension until the slips are freed to move to their retracted positions.- The slips 39 engaging the upper end of the core are substantially held against downward movement and as the drilling proceeds the sleeve 38 moves downwardly with the rest of the drill allowing the relatively stationary slips 38 to move outwardly to their retracted positions. Thus it will be seen that the core is received in the drill and passed through the core catcher without being excessively muti- When a sufficient length of core has been ob- I tained or drilled, the drill is pulled upwardly or raised to actuate the core catcher. Upward movement of the drill results in upward movement of the slips 39 and the other parts of the core catcher. The spring urged dogs 31 cooperate with the core hold or tend to hold the body 35 against movement so that upward movement of the drill results in upward movement of the sleeve 38 relative to the slips 39. The inclined surface 54 of the upwardly moving sleeve 38 cooperates with the outer sides of the slips to force the slips inwardly into tight gripping engagement with the core. The pivoted dogs 31 bite into the core as the core catcher is caused to move upwardly with the drill due to the engagement of the slips with the core. The slips 39 and the dogs 31 gripping the core cause the core to be broken free from the formation as the drill moves upwardly and dependably hold and retain the core as the drill is withdrawn from the well bore.

The body 35 and the parts carried by the body 36 are free to float or be non-rotatable when the drill is rotated during the coring operation. The body 35 freely floats in the opening 36 and the slips 39 engage or bear on the floating sleeve 38 Thus all parts of the core catcher are free to float or be non-rotatable. This is important as it does not subject the slips or the flexible members carrying the slips to twisting strains or turning strains due to the engagement of the slips with rotating parts of the drill. When the drill is to be taken apart at the derrick the sub i3 is unthreaded from the pin i2 allowing the inner barrel 20 to be withdrawn from the outer barrel l0. When the sub I3 is disengaged from around the core catcher and the inner barrel 20 is removed from the outer barrel, the core may be removed from the inner barrel in any suitable manner with the core catcher remaining on the protruding part of the core. Following the removal of the core the slips 39 may be easily freed from the core by pressing the sleeve 38 toward the body 35 thus releasing the slips 39 for outward movement. Continued pressure on the sleeve 38 in this direction releases the dogs 31 so that the core catcher is freely removable from the core.

Having described only a typical preferred form and application of my invention, I do not wish to be limited or restricted to the specific details herein set forth, but wish to reserve to myself any variations or modifications that may appear to those skilled in the art or fall within the scope of the following claims:

Having described my invention, I claim:

1. A core catcher for use in a tubular core drill including, a sleeve adapted to be arranged in the core receiving opening of the drill, the sleeve having an internal surface inclined downwardly and inwardly relative to the longitudinal axis of the drill, a body adapted to be arranged in the opening below the sleeve, slips operable to grip the core through longitudinal cooperation with the said inclined surface, and means connecting the slips with the body to move therewith.

2. A core catcher for use in a tubular corq drill including, a sleeve adapted to be arranged in the core receiving opening of the drill, the sleeve having an inclined internal surface, a body adapted to be arranged in the opening below the sleeve for free longitudinal and rotative movement relative to the drill, flexible members projecting upwardly from the body, and slips on the members to move with the body and cooperating with said surface to be actuated against a core by relative longitudinal movement between the body and sleeve.

3. A core catcher for use in a tubular core drill including, a sleeve adapted to be arranged in the drill for free rotative movement relative to the drill and for longitudinal movement with the drill, the sleeve having an inclined internal surface, a body adapted to be arranged in the drill below the sleeve for free longitudinal and rotative movement relative to the drill, members attached to the body and extending upwardly therefrom, and slips on the members cooperating with said surface of the sleeve to be actuated by relative longitudinal movement between the drill and body.

4. A core catcher for use in a tubular core drill including, a sleeve adapted to be arranged in the drill for free rotative movement relative to the drill and for longitudinal movement with the drill, the sleeve having an inclined internal surface, a body adapted to be arranged in the drill below the sleeve for free longitudinal and rotative movement relative to the drill, means on the body for cooperating with a core to resist movement of the body, members attached to the body and extending upwardly therefrom, and slips on the members cooperating with said surface of the sleeve to be actuated by relative longitudinal movement between the drill and body.

5. A core catcher for use in a tubular core drill including, a sleeve adapted to be arranged in the drill for free rotative movement relative to the drill and for longitudinal movement with the drill, the sleeve having an inclined internal surface, a body adapted to be arranged in the drill below the sleeve for free longitudinal and rotative movement relative to the drill, core gripping dogs on the body, members attached to the body and extending upwardly therefrom, and slips on the members cooperating with said surface of the sleeve to be actuated by relative longitudinal movement between the drill and body.

6. A core catcher for use in a tubular core drill including, a sleeve adapted to be arranged in the drill for free rotative movement relative to the drill and for longitudinal movement with the drill, the sleeve having an inclined internal surface, a body adapted to be arranged in the drill below the sleeve for free longitudinal and rotative movement relative to the drill, pivoted dogs on the body, springs for urging the dogs against a core to resist movement of the body, members attached to the body and extending upwardly therefrom, and slips on the members cooperating with said surface of the sleeve to be actuated by relative longitudinal movement between the drill and body.

'7. In a core drill having spaced opposing internal shoulders, the combination of, a sleeve arranged between said shoulders for free rotation and for movement longitudinally with the drill, the sleeve having a tapered internal surface, a body arranged in the drill below the sleeve for rotative and longitudinal movement relative to the drill, members on the body projecting upwardly therefrom, and slips attached to the members and cooperating with said surface to be actuated by relative longitudinal movement between the body and drill.

8. In a core drill having spaced opposing internal shoulders, the combination of, a sleeve arranged between said shoulders for free'rotation and for movement longitudinally with the drill, the sleeve having a tapered internal surface, a body arranged in the drill below the sleeve for rotative and longitudinal movement relative to the drill, core gripping means on the body adapted to cooperate with an entering core to resist movement of the body, members on the body projecting upwardly therefrom, and slips attached to the members and cooperating with said surface to be actuated by relative longitudinal movement between the body and drill.

9. In a core drill having spaced opposing internal shoulders, the combination of, a floating sleeve arranged between the shoulders to move longitudinally with the drill, a floating body ar-- ranged in the drill for free longitudinal movement, reins secured to the body and extending through the sleeve, and slips connected with the reins to move with the body and operable to grip a core through cooperation with the sleeve.

10. In a core drill having spaced opposing internal shoulders, the combination of, afloatingsleeve arranged between the shoulders, to move longitudinally with the drill, a floating body arranged in the drill for free longitudinal movement, means on the body engageable by-a core to resist movement of the body relative to the core, and slips. connected with the body to move therewith and cooperating with the sleeve to be actuated against the core. upon upward movement of the drill. v

11. In a core drill having spaced opposing internal shoulders, the combination of, a floating sleeve arranged between the shouldersto move longitudinally with the drill, the sleeve havingan inclined inner surface provided with vertical grooves, a floating body in the drill below the sleeve shiftable longitudinally in the drill, flexible members attached to the body and project-1 ing upwardly therefrom to extend into the grooves, and slips on the members cooperating with said surface to be actuated against the core upon upward movement of the drill.

12. In a core drill, a tubular member having an axially facing internal shoulder, a second member removable from the first'member and presenting an internal shoulder spaced from and opposing the first shoulder, and a core catcher including a floating sleeve arranged between the shoulders of the drill members, a body arranged in one of said members to float and shift longitudinally therein, and slips carried by the body to cooperate with the sleeve and be actuated thereby upon longitudinal movement of the drill, the sleeveand body being free for removal upon disconnection of the members.

13. In a core drill, a tubular member having an axially facing internal shoulder, a second member removable from the first member and presenting an internal shoulder spaced from and opposing the first shoulder, and a core catcher including a floating sleeve arranged between the shoulders of the drill members, a body arranged in one of said members to float and shift longitudinally therein, core engaging dogs on the body ranged between said. shoulders for free rotation and for movement longitudinally with the drill, the sleeve having a tapered internal surface, a

. body arranged in the drill for rotative'and longitudinal movement relative to the drill, flexible members projecting from the body, and slips carried on the members and operable by said surface upon upward movement 0'! the drill.

15. A core recovering means for use in a tubular' core drill including, a sleeve for arrangement in the core receiving opening ofthe drill, a free floating body for arrangement in said opening below the sleeve, upwardly projecting'reinson the body extending into the sleeve, and core gripping parts on the reins operable through engagement with the sleeve. v

- JOHN H. HOWQRQ. 

